Loader bucket position control mechanism



June 14, 1955 E. E. DORKINS LOADER BUCKET POSITION CONTROL MECHANISM Filed Jan. 25. 1951 2 Sheets-Sheet 1 INVENTOR. fl d/P' 5 Dork/'08 ATTORNEYS June 1955 E. E. DORKINS 2,710,699 I LOADER BUCKET POSITION CONTROL MECHANISM Filed Jan. 25, 1951 2 Sheets-Sheet 2 5 4)? E. Oorhhs ATTOEIVEYJ United States Patent LOADER BUCKET POSITION CONTROL MECHANISM Evan E. Dorkins, Ottawa, Kans., assignor to Ottawa Steel, Inc., Ottawa, Kans., a corporation of Kansas Application January 25, 1951, Serial No. 207,762

2 Claims. (Cl.2'14--140) a This invention relates to improvements in power lifts for tractors or the like, such as power shovels and/or loading machines having a scoop or bucket for handling dirt or other substances, and more particularly to mechanism for controlling position of a bucket adapted for swinging movement about horizontal axes for receiving, lifting and tilting to discharge positions materials contained therein.

The various types of power shovels, loading machines and lift attachments for tractors or the like have buckets or material carrying devices on the forward ends of load lifting radius arms which are raised and lowered by suit able mechanism such as hydraulic cylinders to cause the bucket to assume the desired position of horizontal elevation. Various latches and hydraulic cylinders operating entirely independent of the lifting mechanism have been used for retaining the bucket in selected relation to the radius arms and effecting tilting of said bucket, but the present inevntion relates to the provision of double-acting, hydraulic means and arrangements thereof relative to the bucket for controlling the position and operation of the bucket or material carrying device. By properly positioning the bucket, hydraulic means and the connections and mountings therefor, the bucket may be positioned and also tilted or overturned independently of its lifting for a variety of uses in digging, excavating and loading, and also effect tilting movement of the bucket relative to the radius arm responsive to lifting thereof to maintain selected level condition of the bucket during such lifting.

The objects of the invention are to provide a loading machine wherein the bucket is pivotally mounted on the outer end of vertically swingable arm or boom structure with improved means for effecting positioning of the bucket; to provide means responsive to movement of the lifting arms to automatically tilt the bucket relative thereto; to provide a loader bucket with hydraulically operated mechanism to tilt the bucket. about. a horizontal axis which operates during swinging of said bucket in a vertical arc to maintain a selected level relation with the ground; to provide an hydraulically operated mechanism arranged relative to the lifting arms and support therefor whereby the bucket position is altered as the lifting arms are operated and also tilted independently of the lifting movement of said arms by operation of said mechanism; and to provide bucket operating mechanism which is economical tomanufacture, positive and eflicient in operation and adapted for hard usage and extended service without encountering mechanical difficulties.

In accomplishing these and other objects of the present invention, I have provided improved details of structure; the preferred forms of which are illustrated in the accompanying drawings, wherein:'

Fig. l is a perspective view of the bucket position control mechanism on a tractor mounted power lift showing the bucket in lowered position for loading or filling.

Fig. 2 is a side elevation of the power lift with the bucket tilted in lifting position.

2,710,699 Patented June 14, 1955 Fig. 3 is a side elevation of the power lift illustrating the hydraulic mechanism as having operated to elevate the bucket to its maximum raised position in the same level relation with the surface as illustrated in Fig. 2, and disclosing in broken lines the position of the control mechanism and bucket for material discharge.

Fig. 4 is a transverse sectional view through the load lifting radius arm and bucket control slide on the line 4-4, Fig. 2.

Fig. 5 is a plan view of the bucket control cylinder and mounting thereof.

Fig. 6 is a transverse sectional view through the load lifting radius arm and bucket control slide on the line 6-6, Fig. 2.

Referring more in detail to the drawings:

. 1 designates a power shovel or loader illustrated as an attachment for a tractor 2 having an hydraulic system or fluid presure supply (not shown) consisting of a fluid storage tank and engine driven pump, however the specific type of tractor forms no limiting part of the present invention.

The attachment is illustrated as having substantially upright members 3 and 4 arranged on opposite sides of the tractor and having lower ends secured to a frame 5. The upper ends of the members 3 and 4 are rigidly connected by a cross member 6 projecting over and across the top of the tractor unit. The upright members 3 and 4 are further supported and braced by means of diagonal 1y extending brace members 7 having ends suitably connected adjacent the upper ends of the members 3 and 4, said brace members 7 extending rearwardly and. being suitably connected to the frame 5. The upright members 3 and 4 preferably each consists of spaced plates 8 and 9 rigidly connected by a plurality of spaced members 10.

Load lifting radius arms 11 and 12 are arranged on opposite sides of the tractor with the rear end of each rotatably mounted on the'portion of the cross member 6 between the plates 8 and 9 for rotation about a horizontal axis. The forward ends of the arms 11 and 12 project beyond the forward end of the tractor, said forward ends being rigidly connected by a cross member 13. Extensions 14 are fixed to each of the arms 11 and 12 and the cross member and project forwardly thereof so that a bucket 15 may be pivotally mounted on the free ends thereof, said bucket having rearwardly extending ears 16 connected by a tubular member 17 to form a rigid bucket extension pivotally mounted as at 18 on the forward ends of the arm extensions 14 for rotation about a horizontal axis, the pivotal mounting of the bucket being rearwardly thereof.

The bucket. preferably has a forward sharp edge 19, a rounded rear portion 20, andan upwardly and forwardly extending portion 21 to provide an open portion 22 which is directed forwardly in loading position and upwardly when in lifting position. In order to raise and lower the bucket, the ends of plungers 23 are pivotally connected as at 24 intermediate the ends of the arms 11 and 12. Each of the plungers operates in telescoping relation to an hydraulic cylinder 25, extending alongside of the tractor between the plates 8 and 9, said cylinders being trunnioned as at 26 on the upright members 3 and 4 intermediate the ends thereof. The cylinders are suitably connected by fiuid pressure hose 27 with the hydraulic fiuid supply of the tractor and suitable control valve (not shown) whereby hydraulic fluid under pressure is simultaneously admitted to the cylinders 25 to forcibly project the plungers 23 outwardly relative to said cylinders. The actuation of the plungers 23 effects the lengthening of the piston and cylinder arrangement and swings the arms 11 and 12 upwardly about the cross member 6. The return movement of the bucket into its original lowered position is brought about by the control of the valve 3 (not shown) for releasing the hydraulic fluid from the cylinders 25, thereby allowing all of the movable or operating parts to settle by gravity back into lowered position.

To tilt or otherwise position the bucket and alter the bucket position as the arms are raised and lowered, double-acting piston and cylinder devices are arranged above and substantially parallel with each of the arms 11 and 12, adjacent the rear ends thereof pivoted on the cross member 6. Each of the cylinders 28 has rear ends pivotally mounted as at 29 on brackets 30 secured to the upright member plates 8 and extending upwardly therefrom whereby the pivot 29 is above the cross member 6 or pivotal axis of the arms 11 and 12. Piston rods 31 extending from the other ends of the cylinders 28 are pivotally connected as at 32 adjacent the upper end of brackets 33 fixed to slide bars 34 arranged alongside of the arms 11 and 12 and slidable longitudinally thereof. In the illustrated structure, the load lifting radius arms 11 and 12 are H-beams or the like with webs 35 in vertical planes whereby the upper and lower laterally extending flanges 36 and 37 form ways for the slide bars 34. In order to retain the rear ends of the slide bars in sliding engagement with the web 35, straps 38 have ends secured to the brackets 33 above and below the liftforward ends of the slide bars operate between the webs 35 and guide ribs 40 suitably secured to the flanges 36 and 37 of the lifting arms to substantially prevent lateral motion of the slide bars, yet permit free sliding action thereof. Links 41 have ends pivotally connected as at 42 to the forward ends of the slide bars 34, the other ends of said links being pivotally connected as at 43 to the rear ends of arms 44 rigidly secured to the bucket 15 and extending rearwardly therefrom above the pivotal connection 18.

It is to be noted that both the lifting arms 11-12 and cylinders 28 are pivotally mounted on stationary supports with the pivotal connection of the cylinders to the support above the pivotal axis of the lifting arms 11 and 12, and that the pivotal connections between the links 41 and arms 44 are above the axis about which the bucket 15 swings on the arm extensions 14. The relative spacing of these pivots is important in the automatic tilting of the bucket relative to the lifting arms during lifting movement of said lifting arms 11 and 12.

Both cylinders 28 have fluid pressure lines leading to a suitable control valve (not shown) whereby both cylinders are controlled simultaneously by application of fluid pressure to said cylinders. When fluid pressure is applied to the rear of the cylinders 28, the pressure forces the piston rods 31 forwardly, moving the slide .bars Y34 and links 41, to apply force at the pivotal connections 43 to swing the bucket forwardly about the pivots 18. When fluid pressure is applied to the forward ends of the cylinders 28, the piston rods 31 are retracted into the cylinders, moving the slide bars 34 and links 41 rearwardly may be maintained in any set or intermediate position while the lifting arms 11 and 12 remain stationary. However, when the plungers 23 are moved relative to the cylinders 25 under influence of fluid pressure to raise or lower the lifting arms 11 and 12, the bucket 15 will be automatically tilted relative to the arms to maintain are on the ground in loading position.

p '7 is applied to the forward ends of the cylinders 28, effecting rearard movement of the piston rods 31, slide bars 34, and links 41, to apply a rearward force on the bucket above the pivot 18 thereby swinging the bucket to the position illustrated in Fig. 2 for lifting. Then application of fluid pressure to the cylinders 25 projects the plungers 23 therefrom, swinging the lifting arms 11 and 12 upwardly about the pivotal axis thereof, and due to the spacing of the pivots 29 of the cylinders 28 above the cross member 6 upon which the lifting arms 11 and 12 are pivoted, the lifting arms move toward the pivots 29, shortening the distance between said pivots 29 and the bucket pivots 18. This, in effect, moves the entire cylinders 28 forwardly relative to the lifting arms 11 and 12, and without altering the relative position of the piston rods 31 and cylinders 28 the slide bars will also move forwardly relative to the lifting arms 11 and 12 whereby instead of the bucket retaining its relative position to the lifting arms 11 and 12 and possibly spilling some of the material from the top of the bucket as it reaches its uppermost limit of movement, the bucket is swung forwardly relative to the lifting arms simultaneously with the upward movement of the lifting arms 11 and 12 to maintain the bucket in substantially the same level relation with the surface on which the tractor operates throughout the swinging of the lifting arms 11 and 12 for raising the bucket. Obviously the reverse of this swinging movement of the bucket will be effected upon the lowering of the lifting arms 11 and 12.

When the bucket is in elevated position, as illustrated in Fig. 3, the material is discharged therefrom by applying fluid pressure to the rear ends of the cylinders 28 to move the piston rods 31 forwardly to move the slide bars 34 and links 41 to swing the bucket 15 forwardly during the lowering of the arms by applying fluid pres sure to the forward ends of the cylinders 28 to retract the piston rods 31 therein and effect rearward movement of the slide bars 34 and links 41. Therefore, the bucket is moved responsive to the raising and lowering of the lifting arms 11 and 12 and is also independently movable to swing the bucket to desired positions while the lifting arms 11 and 12 are either moving or stationary.

It is believed obvious that I have provided a loader bucket position control mechanism and mounting therefor relative to the load lifting radius arms to provide an efficient, positive tilting or swinging of the bucket.

What I claim and desire to secure by Letters Patent is:

1. In a power lift having a tractor mounted supporting structure with lifting arms pivotally mounted thereon. said lifting arms extending forwardly of the tractor and being swingable in a vertical are, a material carrying device pivotally mounted adjacent the forward ends of the lifting arms for rotation about a horizontal axis, a link having pivotal connection with the material carrying device in vertically spaced relation above the pivotal mounting of said material carrying device, means for tilting the material carrying device comprising hydraulic means having a cylinder pivoted at one end at a fixed point of the supporting structure in vertically spaced relation above the pivotal mounting of the lifting arms and a plunger projecting from the other end of the cylinder, the spacing of the pivotal connection of the cylinder on the supporting structure from the pivotal mounting of the lifting arms substantially corresponding to the spacing of the pivotal connection of the link and material carrying device from the pivotal axis of the material carrying device, and a slide mounted on and movable longitudinally of the lifting arms and connect ing the plunger and link whereby operation of the hydraulic means selectively rotates and positions the material carrying device independently of movement of the lifting arms, swinging movement of the lifting arms about the pivotal mounting thereof causes simultaneous swinging movement of the hydraulic means about its respective pivotal mounting and effects relative longitudinal movement of the slide and lifting arms to tilt the material carrying device to maintain the level relation thereof.

2. In a power lift having a tractor mounted supporting structure with lifting arms pivotally mounted thereon, said lifting arms extending forwardly of the tractor and being swingable in a vertical arc, hydraulic means pivotally mounted on the supporting structure and having engagement with the lifting arms for raising and lowering the lifting arms, a material carrying device pivotally mounted adjacent the forward ends of the lifting arms for rotation about a horizontal axis, slide bars mounted on and extending longitudinally of the lifting arms, links pivotally connected to the end of the slide bars adjacent the forward ends of the lifting arms and having pivotal connection with the material carrying device in vertically spaced relation above the pivotal axis thereof, guide means on the lifting arms for defining the path of movement of the pivotally connected portion of the slide bars and links longitudinally of said lifting arms and limiting relative lateral movement thereof, a second hydraulic means comprising cylinders pivoted at one end at a fixed point of the supporting structure in vertically spaced relation above the pivotal mounting of the lifting arms and plungers projecting from the other end of the cylinders, the spacing of the pivotal connection of the cylinderson the supporting structure from the pivotal mounting of the lifting arms substantially corresponding to the spacing of the pivotal connection of the links and material carrying device from the pivotal axis of said material carrying device, upwardly extending brackets fixed on the slide bars, and means pivotally connecting the plungers to the brackets above the lifting arms whereby operation of the second named hydraulic means selectively rotates and positions the material carrying device independently of movement of the lifting arms and operation of the first named hydraulic means for raising and lowering the load lifting arms effects simultaneous swinging movement of the lifting arms and second named hydraulic means about the respective pivotal mountings thereof effecting relative longitudinal movement of the slide bars and lifting arms to tilt the material carrying device and maintain the level relation thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,311,671 Larsen Feb. 23, 1943 2,377,112 Strunk May 29, 1945 2,395,622 Galbreath Feb. 26, 1946 2,482,612 Drott et al Sept. 20, 1949 2,530,414 Wells Nov. 21, 1950 2,537,010 Andersen Jan. 9, 1951 2,556,592 Markkula June 12, 1951 2,590,454 Pilch Mar. 25, 1952 2,598,685 Greenlief June 3, 1952 2,603,374 McNamara, Jr. July 15, 1952 2,628,731 Reuter Feb. 17, 1953 

